Silica uptake availability is dependent upon pH, temperature, salinity, silica concentration, and the presence of solids.
Si amendments or additives can be applied as a foliar or as a soil amendment. It is not recommended to mix silica supplements with other fertilizers as the alkaline nature of silicon will likely cause precipitation of other nutrients. This can also cause a large pH shift in the growing medium, further limiting the availability of other nutrients. Silica also may compete for uptake with phosphate since they are chemically similar. Caution should be used to avoid combining the two in nutrient solutions in order to prevent competition.
There are also other interactions that come from mixing certain elements in the wrong order. I thought it was commonly agreed that silica products go in first to avoid this from happening ?
I also partly disagree with what he is saying about not using it in the soil. You said it yourself , it needs to be broken down by bacteria / microorganisms for it to become available. How else is that supposed to happen ?
PH is logarithmic on the scale of 0-14 with 7 neutral ph’ at either 6-8 is 10 times more acidic or basic than 7 however since its log a ph of 5 or 9 is 100 times more than neutral … need to have a great ph meter or pen and literally a drop of up/down when working with RO you can get drastic changes Very quickly and can be a BIG PIA !
Citrus acid is a weak acid and breaks down quickly and raises the PPM too high. It’s not well suited as a pH down. Use a strong acid for pH down. Either nitric, sulfuric, or phosphoric acid.